The invention is based on a wrapper shaping apparatus for packages. An apparatus of this kind known from German Pat. No. 694 305 and U.S. Pat. No. 3,140,643 has lateral folders, of which the folding edge in the upper position of the lateral folders is located in approximately the same plane as the top of the shaping mandrel, with air blower nozzles assigned to them. The air blower nozzles blow streams of air at the initially horizontally oriented side portions of the blank, thereby wraping them against the side walls of the shaping mandrel as the lateral folders move upward. The outer portions of the blank, which wrap around the top of the shaping mandrel, are also supposed to be set upright, out of their horizontal position, by the blown air streams so that the folding slides will grip these portions of the blank securely. The ends of the blank that are to be folded over are relatively unstable in shape, especially when the blank is made of a relatively non-rigid packaging material such as paper or thin foils, which means there is a danger that creases will be formed. This danger is especially great when the folding devices operate at high speed. Accordingly, there is a need for a wrapper shaping apparatus in which the blank is guided in a defined manner as it is being folded about the shaping mandrel, especially when its end portions are being folded over.